Compensating foot and thread trimmer assembly



Mara! 1954 K. F. DIEHM ETAL COMPENSATING FOOT AND THREAD TRIMMER ASSE ZMBLY Filed April 21, 1961 2 Sheets-Sheet 1 FIG FIG.

INVENTORS KENNETH R DIEHM; BY FE LIXLLEONABD ATTORNEYS United States Patent Office 3,124,089 Patented Mar. 10, 196.4

3,124,089 COMPENSATING FOOT AND THREAD- TRIMMER ASSEMBLY Kenneth F..Diehm, Temple, and Felix I. Leonard, S nking Spring, Pa., assignors to Trim-Master Corporation, Reading, Pa., a corporation of Pennsylvania Filed Apr. 21, 1%1, Ser. No. i,589' 4 Claims. ((1. 112-252)" This invention relatesto a combination compensating presser foot and thread trimmer.

In particular, this inventionrelates to an improvement overthe combination presser foot and thread trimmer disclosed'in US. patent to Artzt et al. No. 2,707,927, issued May 10, 1955. Said prior patent discloses a presserfoot incorporating knives for cutting or trimming the thread at the conclusion of a sewing operation.

One object of this invention is to-provide a combination presser foot andthread-trimmer, wherein the presser foot is a compensating presser foot. Another object of this invention 1 is to provide a combination compensating Presser-foot and thread trimmer, wherein the compensating movement of the presser foot does not interfere with the thread trimming operation.

In accordance with a preferred embodiment of the invention, the improved combination compensating presser foot and thread trimmer comprises a presser footbody having a recess inthe bottom thereof extending to the sides thereof and having a vertical through bore extending into the recess. A spindle or pivot blade pin is turnably and vertically slidably receivedwithin the body bore and has an enlarged head mounted thereon and spaced above the body, this head being preferably a part of a lever which may be manipulated so asto rotate the spindle and'thereby move the. blades. A respective thread holding blade and cutting blade areturnably received within the recess and fixed to the bottom of the spindle. Spring means provided. between the head and the body urge the blades upwardly, so that they exert the proper holding cutting action upon the thread. The body has-a central longitudinal slot extending to the front thereof and also into the recess, the blades passing across the slot when moved from one side of. the recess to the other side thereof, so as to cut'a thread extending vertically through the recess.

The above is substantially in accordance with the disclosure of the aforesaid prior Artzt et a1. patent. However, the presser foot underlying tie body, in accordance with the invention, is divided into a main presser foot or shoe, and an. auxiliary or compensating'foot. The'shoe underlies the body and has a slot coinciding with the'b'ody slot. The shoe has its-bottom cut away on one side of the-shoe slot so as to reduce its thickness. The thicker partof theshoe has longitudinally spaced main shoe posts fixed. thereto and upstanding therefrom; The body has vertical :boresextending to the bottom thereof and slid ably receivingthe aforesaid posts;

The thicker side of the shoe extends forwardly of the body and is preferably upwardly inclined in front of the body.* The-compensating-presser foot has a rear portion of reduced'thickness which is about the same as the thick-* ness of the cut away portion of the'main' presserfoot or shoe and is received in the cut away portion of said shoe. Forwardly of the body, the-compensating foot is of the 2 same thickness as the main shoe. The thinner part of the'comp'ensating fo'ot has longitudinally spaced compensating-foot posts fixed theretoand upstanding therefrom.

The compensating foot posts extend into bores formed in the bottom of the base. Coil springs extend around the compensating foot posts and extend clearingly'through vertical bores in-the cut away portion of the shoe. The coil springs around the compensating foot posts extend between the compensating foot and the cut away portion of the shoe and normally maintain the bottom of the compensating foot below the bottom of the shoe.

When the presser foot assembly is placed upon the Work,the compensating foot compensates for unevenness in the fabric being sewed, as when a pocket is being sewed. On the other hand, the upward movement of the com pensating foot is limited by its engagement against the bottom-of the cut away portion of the shoe, at which point the bottom faces of the compensating foot and of the thicker portion of the shoe are approximately in a common plane. It will also be apparent that-the action of the compensating foot does not interfere in any way with the operation of the trimmer attachment. Thus, just as in the aforesaid Artzt et a1. patent, the blades may'move up and down to compensate for different thread thicknesses, the shoe having vertical 'play so as to permit this movement of the blades, with the shoe nevertheless being held against the blades for the cutting operation by the pressing of the presser'foot against the work, and with the shoe having a cutting edge then' cooperating with the cutting blade.

Other objects and advantages ofthis invention will becomeapparent-from the following description, in conjunction with the annexed drawing, in which preferred embodiments oft-he invention are disclosed.

In the drawing:

FIG. 1- is a side elevation ofa sewing machine, showingthe improved combination compensating presser foot and thread trimmer in accordance with this invention mounted on the sewing machine.

FIG. 2 is a front elevation of the combination compensating presser foot and thread trimmer in accordance with the invention.

FIG. 3 is a rear elevation of the foot.

FIG. 4 is an enlarged side elevation of the presser foot, viewed from the opposite side as in FIG. 1, and partly broken 'away.

FIG. 5 is a section on line55 of FIG. 2.

FIG. 6 is a section on line 66 of FIG. 4.

FIG. 7 is a section on line 7-7 of FIG. 4.

FIG. 8 is a view similar to FIG. 7, but showing the knives moved in a cutting operation.

FIG. 9 is a cross section of the'pivot blade pin, showing the'holding blade and cutting blade in top plan View.

Upon reference to the drawings in detail, it will be noted that they show a presser foot body as which is longitudinally elongated and which has arear portion of increased height. Said body 64 has a recess '76 in the bottom theerof, this recess '76 extending to the sides of body'64 and terminating short of the front and rear thereof. Body 64 also has a central longitudinal slot 66 which extends to the front thereof and also into recess 76.

Near the rear thereof, body-64 has a central vertical through bore 74, extending'between recess 76 and the top of base 64. Thebottom portion of bore'74 is of some what enlarged diameter, and the top portion of bore 74, designated by the reference numeral 74a, is also of enlarged diameter.

Spindle or pivot blade pin 78 extends turnably and slidably through bore 74, the lower portion 8t! of said pin 78 being of increased diameter so as to be retained in said lower bore portion against vertical movement therefrom. Pin 78 extends above the upper face of base or body 64. The upper end of pin 73 extends into a vertical through bore of knife lever 96, said lever 96 being fixed to pin 78 by set screw %a or any other suitable means. Coil spring 98 extends around pin 78 and into bore portion 74a, and extends between body 64 and lever 9-5 and biases pin 78 to its uppermost position.

Upper thread holding blade 86 and lower thread cutting blade 84 are turnably received within recess 76. The rear portions of blades 34 and 86 extend into a diametrical through slot 82 in the bottom of pin portion 8%, and are fixed to the bottom face of pin portion 8%) by means of screw 88. The front portions of blades 84 and 35 extend forwardly of the rear end of slot 66, so that the blades cross slot 66 as they are moved from one side of recess 76 to the other side of recess 76 by manipulation of knife lever 96.

As shown in FIG. 9, the forward ends of the cutting and holding blades 84 and 86, respectively, are offset laterally with respect to the shanks thereof, with the underlying cutting blade 84 having a forward portion which is offset a greater distance than the forward portion of the superposed thread holding blade 8d so that during swinging of the blades in the counterclockwise position, as viewed in FIG. 9, the leading edge E of the holding blade will proceed the leading or cutting edge 92 of the cutting blade. The leading edge 90 of the holding blade is rounded, while the cutting edge 92 of blade 84 is cut perpendicular to the surfaces of the blade.

In accordance with the particular improvement of this invention, the presser foot is in two parts, one part being designated as the main presser foot or shoe 1, and the other part of the presser foot being designated as the auxiliary presser foot or compensating presser foot 2.

Said shoe 1 has a rear portion which is generally coextensive in area with the bottom of body 64, and which underlies body 64. On one side, shoe 1 has a portion 3 which projects forwardly of body 64 and which is upwardly inclined. Shoe 1 has a central longitudinal slot 70 extending to the front thereof and coextensive at one side thereof with the inner side edge of shoe portion 3. Said slot 70 registers with slot 66 in body 64.

On the side of shoe 1 which is opposite from extension 3, its bottom is provided with an undercut 4. This undercut 4 extends between slot 70 and the outer edge of shoe 1, and also extends between the front and rear of the shoe. On the side of shoe 1 at which its extension 3 is located, it is provided with a pair of longitudinally spaced upstanding screws or posts 72 at the front and 72a at the rear. Each of said posts 72 and 72a has a bottom screw threaded extension 73 of reduced diam eter which is threaded into a corresponding screw threaded recess in shoe 1. Each of said screws or posts 72 and 72a extends turnably and slidably into a corresponding vertical bore 75 and 75a respectively in base or body 64. The rear screw 72a is provided with an enlarged upper head 7212 which is received in a corresponding enlarged portion of bore 75a to prevent separation of shoe 1 from body 64.

Compensating foot 2 has a rear portion 2a of reduced thickness corresponding in area to and received within undercut 4. In other words, the width of the portion 2a corresponds to the width of undercut 4, and the portion 2a extends to the rear of undercut 4. Compensating foot 2 also has a front portion 2b which extends forwardly of base 64 and is of increased thickness corresponding to the thickness of the main portion of shoe 1, as shown in FIG. 4 so as to extend above the level of foot portion 2a. However, the foot portion 2b is optionally and preferably not inclined, also as shown in FIG. 4.

Front post or screw 5 and rear post or screw 6 extend upwardly from the reduced thickness portion 2a of compensating foot 2. Each of said posts or screws 5 and 6 has a bottom extension 5a and 6a respectvely of reduced diameter which is screw threaded and which is screwed into a corresponding screw threaded bore in foot portion 2a. Said posts 5 and 6 extend clearingly through respective vertical through bores 5b and 6b in the reduced thickness portion of shoe 1 and also, extend turnably and slidably into respective bores 5c and 6c in body 64. The rear post 6 has an upper head 6d of increased diameter received within a portion of bore 6c of increased diameter so as to prevent separation of compensating foot 2 from body 64.

Respective coil springs 7 and 8 extend around posts 5 and 6, extend clearingly through bores 51) and 6b and also extend between compensating foot 2 and body 64, so as to urge compensating foot downwardly.

As is clearly shown in FIGS. 2 and 3, compensating foot 2 is normally located below the level of shoe 1, so as to compensate for differences in thickness of the material being worked on. However, compensating foot 2 is capable of being elevated until it is located approximately with its bottom face level with the bottom face of the main portion of shoe 1.

The manipulation of lever 96 is accomplished by means substantially the same as those shown in the aforesaid prior patent to Artzt et al. No. 2,707,927, and reference is made to that patent to complete the disclosure herein. The improved combination compensating presser foot and thread trimmer in accordance with this invention may be used in conjunction with a conventional sewing machine generally identified by the reference numeral 10, wihch may be of any conventional type used in sewing garments. The head 13 carries a vertical reciprocating needle bar 20 in which is attached a needle 22 having an eye for receipt of the top or over thread T. The sewing machine 10 further includes an automatic top thread tension 24 and a vertically movable thread take-up lever 26, as well as the usual drive means for reciprocating needle bar 20 and raising nad lowering the thread take-up lever.

The presser foot assembly is generally designated by the reference numeral 30 and is secured to the lower end of a vertically movable presser bar 32 disposed adjacent to needle bar 20. Presser bar 32 may be raised and lowered by any suitable means (not shown). In the lowered position of presser bar 32, shoe 1 and compensating foot 2 bear upon cloth carried on cloth plate 40 mounted upon bed 12.

The presser foot assembly 30 includes a support member 58 having an upwardly open bore in which bar 32 is received and removably secured and a bifurcated lower portion providing a pair of spaced apart legs 60. A lateral hollow split spring pin 62 is carried by the legs 60 and extends turnably through a lateral bore in base or presser foot body 64, forwardly of pin 78 and adjacent the top of the body, base 64 may be rocked about axis of pin 62.

Actuating lever is rockably mounted adjacent its center, by means of screw 102, upon the back of support member 58 of presser foot assembly 34 to swing in a vertical, laterally extending plane. At its lower end, lever 100 is formed with a vertically extending slit 104 receiving a spherical knob 31% at the free end of actuating lever 96. As a result, rocking of lever 100 about the axis of its pivot N2 is converted into angular displacement of lever 96 and spindle 78 about the vertical axis of spindle 78 for turning of the blades 84 and 86.

Bent lever 168 is rockably mounted, intermediate its ends, as at 11%), on the back of head 18 of sewing machine 10 for swinging laterally, that is in a plane parallel to the plane of movement of lever 100. At its lower end, lever 108 is formed with a vertically elongated slot 112 which slidably receives a pin 114- projecting from the upper end of lever 160 thereby totrans mit angular disbursement of lever 168 to lever 100 of presser foot assembly -At its upper end, lever 108 is provided with a connection means 116 for connection to actuating means for lever 168 (not shown) Inop eration, when the presser foot. is lowered onto the work, with upper thread T passing through the slots 66 and 70 in the. usual manner, the floatingshoe 1 is raised relative to body 64 so as to bear against the lower surface thereof. It is understood that there is no bias against upward movement of shoe 1, while there is spring bias against the upward movement of compensating foot 2. Accordingly, if, for example, the shoe 1 passes over a pocket, with compensating foot 2 passing over the main portion of the fabric, the compensating foot will continue to press firmly against the cloth. As shown in FIGS. 7 and 8, at the conclusion of the sewing operation, when the needle has been moved to a raised position and thereby withdrawn from the slots 66 and 70, spindle 78 is angularly manipulated to move the blades 84 and 86 laterally across recess 76 and past the slots 66 and 70. During such movement of the cutting and holding blades, edge 90 of the holding blade 86 first comes into contact with the thread T extending through the slots 66 nad 70, and the thread is pushed to the side and gripped or held between the upper surface of holding blade 86 and the lower surfaces of body 64 to one side of slot 66. After the thread has been gripped or held in the above manner, continued lateral movement of the cutting and holding blades brings the cutting edge 92 of cutting blade 84 across the sharp corner of cutting edge 94 of the presser foot control 1 and thereby shears or cuts the thread T.

As a result of the action of spring 98, the holding blade 86 is held against the upper surface defining recess 76 so that threads of different counts can be held or gripped between the holding blade and the upper surface of the recess without requiring adjustment of the presser foot assembly. For example, if a relatively thick thread is used, the blades 84 and 86 are displaced downwardly with the spindle relative to body 64, and the floating mounting described above for presser foot shoe 1 permits such downward displacement of the holding and cutting blades. In view of the yieldable mounting of compensating foot 2, there is no interference with this downward displacement of shoe 1 and the blades 84 and 86. Since the cutting and holding blades of presser foot assembly 30 are operated only when the presser foot assembly is in its lowered or cloth holding position, the pressure of the presser foot assembly on the stitched cloth is sutficient to urge shoe 1 into cutting relationship with respect to blade 84.

From the foregoing, it will be apparent that there has been provided a combination presser foot assembly and thread trimmer, wherein the presser foot assembly incorporates a compensating foot to compensate for variation in thickness of the fabric being sewed, with said compensating foot not interfering in any way with the desired thread trimming action.

While a preferred embodiment of the invention has been disclosed, and various possible changes, omissions and additions which may be made in the invention have been indicated, it will be apparent that various other changes, omissions and additions may be made in the invention without departing from the scope and spirit thereof.

What is claimed is:

1. Compensating foot means for a combination presser foot and thread trimmer assembly, said assembly comprising a presser foot body having a recess in the bottom thereof, cutting blades received within said recess and means mounting said blades vertically adjustably and turnably against the bottom of said body; said compensating foot means comprising a shoe underlying said body, means mounting said shoe at the front and rear thereof vertically slidably on said body, said mounting means for said shoe being located on one side thereof, the other side of saidshoe having its bottom cutaway so as to reduce itsthickness, a compensating foot mounted .on said, as-

sembly within-said shoe cutout, said compensating afoot. having frontand rear posts extending upwardly there: frorn,-. coil springs extending around said compensating sating foot'posts, said compensating foot springs extending between said compensating foot and said shoe and normally maintaining said compensating foot with the bottom thereof substantially below the level of the bottom of said shoe, said compensating foot being upwardly movable to a level in which the bottom of said compensating foot is approximately in the same plane as the bottom of said shoe.

2. Improvement in accordance with claim 1, said compensating foot means also including means for preventing separation of said compensating foot from said body.

3. Compensating foot means for a combination presser foot and thread trimmer assembly, said assembly comprising a presser foot body, said body having a recess in the bottom thereof extending to the sides thereof and having a vertical through body bore extending into said recess, a spindle turnably and vertically slidably received within said body bore and having an enlarged head spaced above said body, cutting blades turnably received within said recess and fixed to the bottom of said spindle, and spring means between said head and said body urging said blades upwardly, said body having a central longitudinal body slot extending to the front thereof and also into said recess, said blades passing across said slot when moved from one side of said recess to the other side thereof; said compensating foot means comprising a presser foot shoe underlying said body and having a shoe slot coinciding with said body slot, said shoe having its bottom cut away on one side of said shoe slot so as to reduce its thickness, the thicker part of said shoe having longitudinally spaced shoe posts fixed thereto and upstanding therefrom, said body having vertical shoe post bores extending to the bottom thereof and slidably receiving said shoe posts, means preventing withdrawal of said shoe posts from their associated bores, said shoe extending forwardly of said body and being upwardly inclined in front of said body, a compensating presser foot having a rear portion of reduced thickness which is the same as the thickness of the cut away portion of said shoe received in the cut away portion of said shoe and having a portion of the same thickness as the shoe located forwardly of said body, the thinner part of said compensating foot having longitudinally spaced compensating foot posts fixed thereto and upstanding therefrom, coil springs respectively extending around said compensating foot posts, said cut away portion of said shoe having through vertical bores through which said compensating foot posts and coil springs extend turnably and slidably, said body having vertical compensating foot post bores extending to the bottom thereof and slidably receiving said compensating foot posts, means preventing withdrawal of said compensating foot posts from their associated bores, said coil springs extending between said compensating foot and said cut away portion of said body and normally maintaining the bottom of said compensating foot below the bottom of said shoe.

4. Compensating foot means for a combination presser foot and thread trimmer assembly, said assembly comprising a presser foot body having a recess in the bottom thereof, cutting blades received within said recess, and means mounting said blades vertically adjustably and turnably against the bottom of said body; said compensating foot means comprising a shoe underlying said body, means mounting said shoe at the front and rear thereof on one side thereof vertically slidably on said body, the other side of said shoe having its bottom cut away so as to reduce its thickness said shoe having vertical through bores therein above said shot cutout, a compensating foot means extending slidably through said vertical shoe bores and mounting said compensating foot in the cut away part of said bottom and vertically and slidably movable on said body, said compensating foot and said shoe being independently movable with respect to said body, and biasing means extending through said vertical shoe bores and coupling said body and said compensating foot and normally maintaining said compensating foot with the bottom thereof substantially below the level of the bottom of said shoe,

References Cited in the file of this patent UNITED STATES PATENTS 1,109,445 McNeil Sept. 1, 1914 1,202,283 Gray Oct.. 24, 1916 1,501,557 Heller July 15, 1924 2,067,965 Klau Jan. 19, 1937 2,707,927 ArtZt et a1 May 10, 1955 

1. COMPENSATING FOOT MEANS FOR A COMBINATION PRESSER FOOT AND THREAD TRIMMER ASSEMBLY, SAID ASSEMBLY COMPRISING A PRESSER FOOT BODY HAVING A RECESS IN THE BOTTOM THEREOF, CUTTING BLADES RECEIVED WITHIN SAID RECESS AND MEANS MOUNTING SAID BLADES VERTICALLY ADJUSTABLY AND TURNABLY AGAINST THE BOTTOM OF SAID BODY; SAID COMPENSATING FOOT MEANS COMPRISING A SHOE UNDERLYING SAID BODY, MEANS MOUNTING SAID SHOE AT THE FRONT AND REAR THEREOF VERTICALLY SLIDABLY ON SAID BODY, SAID MOUNTING MEANS FOR SAID SHOE BEING LOCATED ON ONE SIDE THEREOF, THE OTHER SIDE OF SAID SHOE HAVING ITS BOTTOM CUT AWAY SO AS TO REDUCE ITS THICKNESS, A COMPENSATING FOOT MOUNTED ON SAID ASSEMBLY WITHIN SAID SHOE CUTOUT, SAID COMPENSATING FOOT HAVING FRONT AND REAR POSTS EXTENDING UPWARDLY THEREFROM, COIL SPRINGS EXTENDING AROUND SAID COMPENSATING 